A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. Additionally, the core of the gas turbine engine general includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air is provided from the fan to an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section to the turbine section. The flow of combustion gasses through the turbine section drives the turbine section and is then routed through the exhaust section, e.g., to atmosphere.
Conventional gas turbine engines include rotor assemblies having shafts, compressor impellers, turbines, couplings, sealing packs, and other elements required for optimal operation under given operating conditions. These rotor assemblies have a mass generating a constant static force due to gravity, and also generate a dynamic force due to, e.g., imbalances in the rotor assembly during operation. Such gas turbine engines include bearing assemblies to sustain and support these forces while permitting rotation of the rotor assembly. A typical bearing assembly includes a bearing housed within a bearing housing and a bearing pad configured between the bearing and the shafts.
Conventional aircraft engines operate using rolling element bearings. Such oil-requiring bearings support static and dynamics loads from the rotating system throughout the operating cycle of the engine. Though rolling elements are a proven technology that have been used since the conception of the jet engine, the necessity for oil requires several support hardware and ancillary devices. Thus, removal of rolling element bearings from the engine system could potentially provide significant weight savings in addition to improved reliability.
Accordingly, at least some known rotary machines use gas bearings where non-oil lubricated bearings are desired. For successful operation, gas bearings must address typical mission cycle loads. As such, at least two hurdles must be considered for gas bearings used in high performance turbomachinery, such as aircraft engines, including 1) load capacity and 2) damping.
In view of the aforementioned, a hermetically sealed damper and damper fluid for a gas bearing and method of filling of same that allows for successful operations at high temperatures would be welcomed in the art.